Analysis of distribution and drug resistance of pathogens of burn patients during 9 years

Objective To investigate distribution and drug resistance of pathogens of burn patients. Methods A total of 3 357 strains were cultured and isolated from 25 286 specimens of wounds excretion, deep venous catheters, venous blood, stool, mid-stream urine, sputum, puncture fluid, and throat swab of 11 510 burn patients hospitalized in our burn wards from January 2007 to December 2015. After being identified by API bacteria identification panels and automatically bacteria identification equipment, drug-resistances of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae to 28 common antibiotics were tested by drug sensitivity test with K-B paper disk diffusion method. The WHONET 5.6 software was used to analyze constituent ratio of gram-negative bacteria and gram-positive bacteria in each year, distribution of pathogens in each year, and drug resistance of the above-mentioned 4 pathogens in 9 years to 28 common antibiotics. Data were analyzed by the linear model curve fitting. Results (1) From 2007 to 2015, constituent ratios of gram-negative bacteria were respectively 41.22% (101/245), 41.88% (165/394), 45.92% (169/368), 42.54% (208/489), 52.35% (267/510), 56.89% (194/341), 58.99% (210/356), 56.95% (172/302), and 50.28% (177/352), with significantly increasing trend (R²=0.625, P<0.05); constituent ratios of gram-positive bacteria were respectively 58.78% (144/245), 58.12% (229/394), 54.08% (199/368), 57.46% (281/489), 47.65% (243/510), 43.11% (147/341), 41.01% (146/356), 43.05% (130/302), 49.72% (175/352), with significantly decreasing trend (R²=0.625, P<0.05). In 9 years, constituent ratio of Staphylococcus aureus ranked the first in all bacteria, and constituent ratios of Pseudomonas aeruginosa and Klebsiella pneumoniae were with significantly increasing trend (R²=0.811, 0.778, P<0.01). (2) In 9 years, drug-resistant rates of Staphylococcus aureus to gentamycin and rifampicin were with significantly decreasing trend (R²=0.727, 0.766, P<0.01); drug-resistant rates of Staphylococcus aureus to phosphonomycin were always in lower levels of 4.6% to 19.5%. In 9 years, drug-resistant rates of Pseudomonas aeruginosa to ceftazidime and ciprofloxacin had no significant change in trend (R²=0.023, <0.001, P>0.05), while drug-resistant rates of Pseudomonas aeruginosa to other 10 common antibiotics were with significantly increasing trend (R²=0.764, 0.793, 0.785, 0.768, 0.752, 0.749, 0.789, 0.786, 0.706, 0.629, P<0.01). In 9 years, drug-resistant rate of Acinetobacter baumannii to ampicillin/sulbactam was with significantly decreasing trend (R²=0.652, P<0.01), and drug-resistant rate of Acinetobacter baumannii to amikacin was with significantly increasing trend ( R²=0.531, P<0.05). In 9 years, drug-resistant rates of Klebsiella pneumoniae to piperacillin, ampicillin/sulbactam, cefuroxime, ceftazidime, cefotaxime, cefepime, imipenem, meropenem, amikacin, and gentamicin were with obviously increasing trend (R²=0.481, 0.672, 0.694, 0.532, 0.810, 0.641, 0.809, 0.709, 0.579, 0.810, P<0.05 or P<0.01). Conclusions Constituent ratios of gram-positive bacteria of Pseudomonas aeruginosa and Klebsiella pneumoniae of burn patients hospitalized in our burn wards from 2007 to 2015 were significantly increased, while constituent ratios of Staphylococcus aureus of those children always ranked the first. Drug-resistence of bacteria of those children in our burn wards was serious. Drug-resistant rate of Staphylococcus aureus only to phosphonomycin was always in lower level. Drug-resistant rates of Pseudomonas aeruginosa to 10 common antibiotics except ceftazidime and ciprofloxacin were significantly increased. Drug-resistant rate of Acinetobacter baumannii only to ampicillin/sulbactam was significantly decreased. Drug-resistant rates of Klebsiella pneumoniae to most common antibiotics were significantly increased.